Births after vitrification at morula and blastocyst stages: effect of artificial reduction of the blastocoelic cavity before vitrification

Abstract

Our results showed that survival rates in cryopreserved expanded blastocysts could be improved by reducing the fluid content. This was presumably because mechanical damage caused by ice crystal formation was avoided. These observations should be considered when establishing a strategy and a protocol for cryopreservation of day 5 embryos.